Rachel Roddy’s recipe for pasta and peas

A square meal from Lazio featuring spring peas and lasagne sheets cut up into stamp-sized pieces

Take a sheet of paper. You can simply use it as is, filling it with words or drawings, or you could roll it into a tube, shred it into ribbons of any width, rip or cut it into any number of squares, or fold it into a boat, hat or peacock. Well, the same applies to sheets of pasta! I am thinking mostly about the sheets of fresh egg pasta that here in Italy come in stacks in cellophane-topped packets. For a long time, I only ever saw these sheets as "sheets to be layered" (their purpose was stated in their name), but even when the packet has "lasagne" printed on the front in big letters, it doesn't mean that's the only way to use them; they are sheets of great potential, to be rolled into cannelloni or sliced into ribbons of any width.

They can also be cut into squares of any size, to wrap around a filling (if the pasta is soft enough, although it generally isn't after days in the packet). I cut sheets into 6cm squares or diamonds for basil and other types of pesto, while for minestrone and other bean soups a 3cm square or lozenge is a good shape and size for a spoon. And the shapes don't need to be neat. Quite the opposite, in fact – maltagliati (meaning badly cut) is one of the nicest shapes of all, and then there are quadrucci, which are little squares that vary in size from postage stamps to mosaic tiles or to the size of a pencil rubber or pea.

Quadrucci e piselli, or squares of pasta and peas, is a dish typical of Lazio, a minestra that's brothy enough to require a spoon (but only just) and dense enough to be filling. Traditional recipes, such as that of Ada Boni, start with il battuto, which comes from the word battere (to hit), which sums up the way you and your knife should approach the cured pork fat, onion, parsley and celery. These recipes also include guanciale or pancetta. Contemporary recipes, however, tend to omit pork and suggest olive oil, so I have, too (as always, though, it is up to you). There is also the question of tomato – a couple of peeled, crushed fresh ones in summer, or a tablespoon of passata or concentrate in winter – which adds both depth of flavour and makes the broth blush.

Wait a few minutes before serving, so the flavours settle, then add some chopped flat-leaf parsley. Cheese (grated pecorino or parmesan) is essential for both seasoning and flavour, so encourage everyone to stir some in and cloud the broth. Dried red chilli pepper flakes are good, too, not least for the flecks of red amid the pasta squares and peas. A meal from a sheet, a game in a bowl.

Serves 4

6 tbsp olive oil1 onion, peeled and finely chopped 1 garlic clove, peeled and finely chopped1 stalk celery with leaves, very finely choppedSalt300g peas (fresh or frozen)1.3 litres water mixed with 1 tbsp tomato concentrate until dissolved, orlight vegetable or chicken stock250g fresh egg pasta sheets, cut into 1cm squaresA few sprigs flat-leaf parsley, finely chopped Grated pecorino or parmesan, to serve Dried red pepper flakes, to serve (optional)

Put the oil, onion, garlic, celery and a pinch of salt in a heavy-based pan, set it over a medium-low heat and fry the vegetables, stirring often, until they are soft and translucent - about eight minutes.

Add the peas, stir for a few minutes, then add the water or stock. Bring to a gentle boil, then reduce to a simmer for 10 minutes. Taste for salt and add more if needed.

Raise the flame, so the soup boils gently, then add the pasta and cook until al dente – the final consistency should be that of a dense soup, but with visible broth.

Add the parsley, then serve, encouraging everyone to stir some grated pecorino or parmesan and red pepper flakes into their bowlful.